This invention relates to the purification of lubricating oils made from fossil fuels and used in internal combustion engines.
The lubrication systems of engines are required for the proper operation of the various parts of an engine such as drive shafts, piston rings, lifters, camshafts, bearings, and the like. However, because of intense heat, lubricating oil impurities, fuel impurities and air impurities, lubricating systems require constant filtration. The most common form of such filtration is to have the lubricating oil pumped through an oil filter for filtering and return to the engine. Most oil filters have inert filtering materials which remove most particulate matter, but are generally ineffective against acidic impurities such as sulfur dioxide and sulfuric acid. Acidic impurities are corrosive and tend over a period of time to damage the working parts of an engine. Accordingly, lubricating oils must be frequently changed and the discarded oils abandoned.
Methods have been proposed in the past for removing acidic impurities from lubricating oil, as indicated in the following United States patents:
U.S. Pat. No. 3,154,488 describes a device for regenerating oxidized mineral oils, comprising a pair of thin magnesium metal plates or wires, as for example, magnesium and silver wires contacting at one point only.
U.S. Pat. No. 3,617,580 describes the circulation of engine lubricating oil through oil-insoluble particles of two or more metallic elements which provide an oxidation-reduction potential.
U.S. Pat. No. 3,279,607, describes an oil filter cartridge which includes non-ferrous metallic substances, as for example, magnesium in the form of bars or stripes spaced within the normal filter materials.
U.S. Pat. No. 4,501,660 describe an oil filter whose central core contains a magnetized metallic helix enclosing longitudinal bars of magnesium metal.
However, the prior art is complex and costly.
One object of the present invention is to provide a more inexpensive means for readily and efficiently removing acidic. impurities from a lubricating oil.
Other objects and advantages of this invention will be apparent from the description and claims which follow taken together with the appended drawings.